Effect of Injury by Catheter Balloon in Wistar Rats Through Time, Characterizing Restenosis

Aim Restenosis and Atherosclerosis are a public health problem worldwide. There are many instances where arterial injury needs repair and regeneration to avoid heart failure and death. For example in atherosclerosis, arterial aneurysms, and restenosis after balloon catheter stenosis. The goal of this study was carry on to characterize the animal model of balloon catheter injury, that characterizes restenosis and identify if the lesion persists for long periods. Also, in restenosis we analyzed the neointimal hyperplasia over time, in rats that underwent balloon catheter injury in the left carotid artery characterizing restenosis. Methods In order to characterize the animal model of balloon catheter injury in male Wistar rats with approximately 400 grams of body weight (n=5/group) were divided into 4 groups (20, 40, 60 and 80 days after injury) and balloon catheter (Fogarty 2F, Edwards Lifesciences) was used to cause the injury that was performed on the left carotid artery and the right carotid artery was used as the control. After the each time the injury the rats were euthanized and the arteries were removed for histological and morphological analysis. The slides were stained with hematoxylin and eosin and the circumference of the external elastic lamina and lumen were used to calculate the thickness of the neointimal (EEL‐lumen = neointimal; μm). One‐way ANOVA was used with Tukey post‐hoc, presented in the mean ± standard error of the mean. Significance level was p<0.05. Results After the injury, the endothelium was removed by the balloon catheter. Twenty days after the injury, we observed the neointimal layer formation between the middle tunica and the lumen, resulting of the proliferation and cellular migration towards the vessel lumen. Twenty days after the injury the neointimal was increased (219087.62 ± 54837 (p<.0001) compared with the control group, after 40 days we observed increase compared to the 20 days (250751 ± 4076; (p<.0001), however, after 60 days was decreased (90024 ± 5514 (p<0.005) compared to control group, 20 and 40 days. The neointimal layer was stabilized with 80 days (97886 ± 13546 (p=0.0266). Conclusion The rats submitted to catheter balloon injury showed an increase in the thickness of the neointimal, characterizing the model as effective to promote mechanical damage in the vessel lumen. These results showed that in the control group the neointimal hyperplasia was null, while the peak of growth was with 40 days after the injury stabilizing with 80 days. Thus, this is an effective model for studies of protocols for the prevention of long‐term restenosis. Support or Funding Information CAPES, CNPq and FAPESP This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .